Multiferroic van der Waals heterostructure FeCl$_2$/Sc$_2$CO$_2$: Nonvolatile electrically switchable electronic and spintronic properties

TL;DR

This study explores a multiferroic van der Waals heterostructure of FeCl₂ and Sc₂CO₂, demonstrating reversible electrical switching between semiconducting and half-metallic states, with potential applications in nanoelectronics and spintronics.

Contribution

It introduces a novel FeCl₂/Sc₂CO₂ heterostructure that can be electrically switched to exhibit different electronic and spintronic properties, including a half-metallic phase with a broken gap band alignment.

Findings

Reversible switching between semiconducting and half-metallic states.

Half-metallic phase shows Type-III broken gap band alignment.

Quantum transport simulation demonstrates all-electric-controlled valving effects.

Abstract

Multiferroic van der Waals (vdW) heterostrucutres offers an exciting route towards novel nanoelectronics and spintronics device technology. Here we investigate the electronic and transport properties of multiferroic vdW heterostructure composed of ferromagnetic FeCl$_2$ monolayer and ferroelectric Sc$_2$CO$_2$ monolayer using first-principles density functional theory and quantum transport simulations. We show that FeCl$_2$/Sc$_2$CO$_2$ heterostructure can be reversibly switched from semiconducting to half-metallic behavior by electrically modulating the ferroelectric polarization states of Sc$_2$CO$_2$. Intriguingly, the half-metallic phase exhibits a Type-III broken gap band alignment, which can be beneficial for tunnelling field-effect transistor application. We perform a quantum transport simulation, based on a \emph{proof-of-concept} two-terminal nanodevice, to demonstrate all-electric-controlled valving effects uniquely enabled by the nonvolatile ferroelectric switching of the heterostructure. These findings unravels the potential of FeCl$_2$/Sc$_2$CO$_2$ vdW heterostructures as a building block for designing a next generation of ultimately compact information processing, data storage and spintronics devices.